1. Field of the Invention
The invention relates to antennas, and particularly to an ultra-wideband (UWB) antenna.
2. Description of Related Art
With the development of short-haul wireless communications and the trend of multi-products for personal mobile communications, transmission traffic of wireless communications is increased, and transmitting rates thereof are accelerated. In view of the above, the federal communications commission (FCC) approves the ultra-wideband (UWB) technology for commercial use in February of 2002, and defines the UWB communication system as a high transmission rate, low power, and short-haul communication system. In addition, the institute of electrical and electronics engineers (IEEE) draws the IEEE 802.15 standard for wireless personal area network (WPAN), which has characteristics of high transmission rate and low power. Presently, under the IEEE 802.15 standard, UWB communication devices are restricted to intentional operation between 3.1 and 10.6 GHz.
In recent years, more attention has been paid on developments of small-sized wireless communication devices, such as mobile phones, wireless cards, and access points, for convenient portability. An antenna, as one of the key elements of the wireless communication devices, has to be miniaturized accordingly. Amended bucolical antennas are often used as UWB antennas, but the size of the conventional UWB antennas is large. Therefore, what is needed is a UWB antenna with a small size.